Thread cutter and clamp for sewing-machines.



F. ZALESKI. THREAD CUTTER AND CLAMP FOR SEWING MACHINES. 4

APPLICAT'WH mi() 1AN.8,19I6

l l @37, mme@ Feb. 2o, 1917,

particular machine herein illustrated', this relative movement issecured by giving movement to the work-clamping means by means of a feedcam shown in dotted lines at 10.` When the machine is brought to rest atthe end of each cycle of operations the parts are in -buttonhole-cuttingposition, as shown in Fig. 1, and the i york clamps 5 are raised. lVhenthe machine is started, the

work clamps are first depressed to clamp the work lw against the clampplates, and then the cutter 9 operates to cut the buttonhole. Thereafterthe feed cam l() moves the workclamping means relative to thestitch-ferne ing mechanism to carry the work from buttonhole-cutting tostitching position and the stitching begins, the work-holding meanshaving a continued feeding movement to effect the formation of thestitches around the edge of the buttonhole. XVhen the stitch.- ing hasbeen completed around the buttonhole, the stitch-forming mechanism isbrought to rest, and the work-holding means and stitch-forming mechanismhave a further relative movement to carry the parts from stitching tobuttonhole-cutting position.

The Ithread clamp which is illustrated in my above-mentioned co-pendingapplication 1s carried by the movable work clamps and is actuated toclamp the needle thread t at the end of the stitching operation andwhile the parts are moving from stitching to buttonhole-cuttingposition. This threadclamping device comprises a fixed clamping jaw 13and a movable clamping jaw r141. `The fixed jaw 13 is carried by an arm15 which is made rigidwith one of the arms 6 by Ameans of a screw 16.The movable jaw 14 is carried by a lever 17 which is pivoted on a stud18 secured to the arm 15. This arm 17 has a pin 20 rising therefromwhich is acted upon by a suitable spring 19, said spring tending to holdthe clamping jaws 13 and 14 closed. The-lever 17 is provided with a camprojection 21 adapted to engage a roll 22 on the end of alever 23 whichis pivoted at 24 to a base plate or support 29 that in turn is securedto the frame 1. This lever 23 has a finger 25 extending therefrom whichplays between two adjustable stop screws 26, 27. During the lstitchingon the buttonhole, the work-clamping means isso position that the roll22 will be at thc right on the cam projection 2l and the stop screws 26,27 are so adjusted that when the parts move from the stitching tobuttonhole-cutoperation, the cam projection 21 will strike the roll 22,as shown in Fig. 2, thereby opening the clamping jaws andV permittingthe needle thread to pass between said jaws as the work clamp is movedbackwardly. Before the parts reach buttonhole-cutting position the roll22 has passed the cam pro. jection 21, thus allowing the clamping jawsto close under the infiuence of the spring 19 and clamping the needlethread, as shown in Fig. 1. iVhen the machine is started again and thework-clamping device is moving` from buttonhole-cutting to stitchingposition, the cam 21 will engage the roll 22 and swing the lever 23 soas to carry' the linger 25 against the stop 26. Said stop is so adjustedthat the finger will be brought into engagement (herewith justfas theiirst stitches on the buttouhole are being formed and as the work clampcontinues its movc` just as the initial stitches are being formed.v

The thread-clamping device` as above dcscribed is such as is illustratedand described in my said co-pending application. 4

By my present invention I have provided a thread-cutting device which isindependent from the thread-clamping means and which is actuated by thelever 23 to cut the needle thread after it has been clamped. My improvedthread-cutter is shown as a cutting blade 30 which is carried on an armor lever 31 that is pivoted to the work clamps. One convenient wayofaccomplishmg this is to pivotally mount the arm 3l en the same stud 18on which the lever 17 upon by a spring 32 which normally holds thecutting blade in its retracted position, and said arm 31 has alsomounted thereon a roll 33 situated to be engaged by the roll 22 duringthe movement of the work-holding means from stitching tobuttonhole-'cutting position and immediately after the roll has acted onthe projection 21. In the opis pivoted. This arm 31 is shown as actedIeration of the device when the stitching on ing mechanism is broughttorest with the needle raised as usual, and the work-clamping means thenmoves toward lthe right, Fig. 2. During this movement the projection 21engages the roll 22 and opens the thread-clamping jaws as shown in Fig.'2, and as the projection wipes by the roll, the jaws will close ontothe thread which has been drawn between them'by the movement of the workclamps, thereby clamping the thread. .Immediately after the thread isclamped the continued movement of the work-clamping means brings thcroll 33 against the roll 22 thereby giving a quick forward movement tothe arm 31 and causing the cutting edge 35 of the cutting blade 30 to becarried against the thread extending between the thread clamp and thework. This portion of. the thread will be held taut so thatthe movementof the cutting blade against it will sever it accurately and withcertainty regardless of the size orl character thereof. It will thus beseen`that the threadcutting device is separate from the. thread clampand is operated subsequently to the clamping of the thread. It will alsobe seen that said thread-cutting' device is actuated by the same meansthat controls the movement of the thread clamp, this means acting rst toeli'ect the clamping of the thread and then the cutting thereof.

I claim:

l. ln a sewing machine, the combination with stitch-forming mechanism,ot' workclamping means, said stiteh-torn'lingmechanism and workclampingmains havinga movement relative to each other during a predeterminedcycle of operations including a stitching operation, a thread clampcarried by said work-clampingmeans above the work, a cutter separatefrom-the thread clamp, and means rendered 'operative' by such relativemovement to cause the thread clamp to clamp the thread at the end of thestitching operation and then to actuate the cutter to cut` the thread.

2. In a sewing machine', the combination with stitch-forming mechanism,of workclamping means, said'stitch-forming `mechanism and work-clampingmeans having a relative movement during aprede terrinined cycle ofoperations includ/inga stitching operation, a pair of thre:-1d-clamp1ngjajws car-l ried by the work-clamping means abfffve the work, a threadcutter separate from said jaws, and means rendered operative by such'relative movement to cause the jthreadclamping jaws to clamp the threadat the.

vend of the stitching operation and subsequently to actuate the cuttertol cut the clamped thread.

3. In a sewingl machine, the combination with stitch-forming mechanism,"of Workclamping means, said stitch-formifiigmechanism and work-clampingmeanslhaving a movement relative to veach other during a predeterminedcycle of operations including a stitching operation, two movablelements,

one adapted to clamp and the .o her to cut `the needle thread above thework ,lheld' 1n the work-clamping means and means to actuate saidelements successively at the end of the stitching operation whereby thehread Will y be first clamped and then cut.

4. In a buttonhole sewing m ichinc, the combination withstitch-forminglmechanism including a reciprocating eye-'poihted needle,ot work-clamping means, means jto give the work-clamping means awork-feeding movement while the edge stitches on abuttonhole are beingformed and an additional movement after the stitching on a buttonholeisthe thread `at the end of the stitching operation and subsequently toactuate the cutter to cut the thread.

,"5..In a buttonhole sewing machine, the combination with a framecarrying stitchforming mechanism, of work-clamping jneans, means to movethe work-clamping neans on the frame thereby to move the ,n vork carriedthereby from stitching to butfton hole-cutting position, a fixed and amov- "i: ble thread-clamping jaw mounted on the work-clamping meansabove thc work held in the work-clamping means, a thread cutterindependent'from said jaws. and also mounted on -said work-clampingmeans, and an actuator carried by said-frame and operating duringsaidmovement of the workclamping means to cause the thread-clamping to clampthe thread and subsequentlyV to actuate the cutter to cut the clampedthread.

combination with a frame carrying stitchforming mechanism, ofwork-holding,r means, means to move the work-holding means 0n the framethereby to more the work from stitching to biittonhole-cutting position,a fixed and a movable thread-clamping jaw mounted on the work-holdingmeans, a cam projection rigid with the movable jaw, a swinging cuttingblade separate from said thread-clamping jaws, and an actuator-carriedby said trame and adapted to engage said cam projection-and actuate themovable thread-clamping jaw and subsequently/to actuate the threadcutter.

- 7. In a buttonhole sewing machine, the combination with a framecarrying stitchforming mechanism, otl Work-clamping means, means to givethe work-clamping means a movement relative to the frame to carry thework from .st-itching tor buttonholc-cutting position, an arm `pivoteelto the Work-clamping means and carrying a threml-clamping jaw, said armhaving a cam projection, a second arm pivoted to said work-clampingmeans and carryinga cutvting blade, said arm also having a projection,and an actuator carried by said ltrame and adapted 'to engage saidprojections successively during the movement of the work-clamjng meansthereby to clamp -and cul. the thread successively'.

8. ln a buttonhole .sewing machine, .the combination with a framecarrying stitchsequently to actuate forming mechanism, of means,- meansto move the Work-clamping means on the frame thereby to move the workcarried thereby from stitching to buttonhole-cutting position, a fixedand a movable thread-clamping jaw mounted on the work-clamping means, athreadcutter independent from said jaws also mounted on saidwork-clamping means, and an actuator carried by the frame and a limitedfree movement in the direction of movement of the work-clamping meansand operating during said movement of the work-clampintg` means to causethe threadclamping jaws to clamp the thread and subsequently to actnatethe cutter to cut the clamped thread.

9. In a buttonhole sewing machine, the combination with stitch-formingmechanism, of work-clamping means said stitch-forming mechanism andforl-clamping means having a movement relative to each other duringapredetermined cycle of operations inelutling, a stitching operation, athread clamp carried by said work-clamping` means above the work, acutter separate from the thread clamp, and means rendered operative 'bysuch relative movement to cause the threadclamp to clamp the thread atthe end of the. stitching operation and then to actuate the cutter tocut the thread and subsaid thread clamp to unclamp the thread.

l0. In a buttonhole sewingmachine, the combination with stitch-formingmechanism, of work-clamping' means, said stitch-form- .ing mechanism andwork-clamping means having a movement relative to `each other during apredetermined cycle of operations includinga stitching operation, athread clamp carried by said work-clamping means above the work, .acutter separate from the work clamping capable of having predeterminedcycle of operations including a stitching operation, a thread clampcarried by said Work-clamping means above the work, a cutter separatefrom the thread clamp, and means rendered operative by such relativemovement to cause the thread clamp to clamp the thread at the end of thestitching operation and then to actuate thecutter t0 cut the thread andto cause said thread clamp to release the thread at the beginning of thenext succeeding stitching operation.

l2. In a sewing machine, the combination with stitch-forming,- mechanismand workclamping,` means, said stitch-forming mechanism andwork-clamping:r means having a movement relative to each other during apredetermined cycle of operations including a stitching operation, twomovable elements, one adapted to clamp and the other to cut the needlethread above the Work held in the work-clampingmeans and means toactuate said elements successively at the end of the stitching operationwhereby the thread will be first clamped and then cut and to actuate thethread-clamping element at thebeginning of the next succeeding operationthereby to release said thread.

In testimony whereof, I have signed my name to this specication.

' FRANK ZALESKI.

